如何从Azure Media Service获取Locator流URL至C#控制器？

嘿，我来帮你搞定在C#控制器里获取Azure Media Services（AMS）Locator流URL的需求！这里有两种常用方案，推荐用官方SDK更省心，当然也可以直接调用REST API，我都给你列出来：

方案一：使用Azure Media Services .NET SDK（推荐） #

官方SDK封装了认证、资源调用等细节，比直接写REST请求更简洁易维护。

第一步：安装NuGet包 #

先把最新的AMS管理SDK安装到项目里：

Install-Package Azure.ResourceManager.Media

第二步：控制器代码示例 #

在你的API控制器里，可以这样实现获取Locator流URL的接口：

using Azure.Identity;
using Azure.ResourceManager.Media;
using Azure.ResourceManager.Media.Models;
using Microsoft.AspNetCore.Mvc;

[ApiController]
[Route("api/media")]
public class MediaController : ControllerBase
{
    private readonly MediaServicesAccountResource _mediaAccount;

    // 从配置读取Azure信息，初始化AMS客户端
    public MediaController(IConfiguration configuration)
    {
        var subscriptionId = configuration["Azure:SubscriptionId"];
        var resourceGroupName = configuration["Azure:ResourceGroupName"];
        var accountName = configuration["Azure:MediaAccountName"];

        var armClient = new ArmClient(new DefaultAzureCredential());
        var subscription = armClient.GetSubscriptionResource(new ResourceIdentifier($"/subscriptions/{subscriptionId}"));
        var resourceGroup = subscription.GetResourceGroup(resourceGroupName);
        _mediaAccount = resourceGroup.GetMediaServicesAccount(accountName);
    }

    [HttpGet("locator-url/{locatorId}")]
    public async Task<IActionResult> GetStreamingLocatorUrl(string locatorId)
    {
        try
        {
            // 根据ID获取指定的Streaming Locator
            var locator = await _mediaAccount.GetStreamingLocatorAsync(locatorId);
            
            // 获取默认的Streaming Endpoint（如果用了自定义Endpoint，替换成你的名称）
            var streamingEndpoint = await _mediaAccount.GetStreamingEndpointAsync("default");
            
            // 拼接完整的流URL：Endpoint主机名 + Locator路径
            var streamUrl = $"https://{streamingEndpoint.Value.HostName}{locator.Value.Path}";

            return Ok(new { StreamingUrl = streamUrl });
        }
        catch (Exception ex)
        {
            return BadRequest($"获取Locator URL失败：{ex.Message}");
        }
    }
}

提示：DefaultAzureCredential会自动适配Azure环境（比如App Service、VM）的认证，本地开发时会用你登录Azure CLI的账号，确保账号有Media Services Contributor权限。

方案二：直接调用REST API（对应你参考的官方文档） #

如果一定要手动调用REST接口，需要先处理Azure AD认证，再发送请求解析响应：

控制器代码示例 #

using System.Net.Http.Headers;
using System.Text.Json;
using Microsoft.AspNetCore.Mvc;

[ApiController]
[Route("api/media")]
public class MediaRestController : ControllerBase
{
    private readonly HttpClient _httpClient;
    private readonly IConfiguration _configuration;

    public MediaRestController(HttpClient httpClient, IConfiguration configuration)
    {
        _httpClient = httpClient;
        _configuration = configuration;
    }

    [HttpGet("rest-locator-url/{locatorId}")]
    public async Task<IActionResult> GetLocatorUrlViaRest(string locatorId)
    {
        try
        {
            // 1. 获取Azure AD访问令牌
            var accessToken = await GetAadAccessToken();
            if (string.IsNullOrEmpty(accessToken))
            {
                return Unauthorized("无法获取Azure AD认证令牌");
            }

            // 2. 构造REST请求URL
            var accountName = _configuration["Azure:MediaAccountName"];
            var location = _configuration["Azure:MediaAccountLocation"]; // 比如"eastus"
            var requestUrl = $"https://{accountName}.restv2.{location}.media.azure.net/api/Locators('nb:lid:UUID:{locatorId}')";

            // 3. 设置请求头并发送GET请求
            _httpClient.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", accessToken);
            _httpClient.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
            _httpClient.DefaultRequestHeaders.Add("DataServiceVersion", "3.0");
            _httpClient.DefaultRequestHeaders.Add("MaxDataServiceVersion", "3.0");

            var response = await _httpClient.GetAsync(requestUrl);
            response.EnsureSuccessStatusCode();

            // 4. 解析响应，提取Locator路径并拼接流URL
            var responseContent = await response.Content.ReadAsStringAsync();
            var locatorJson = JsonDocument.Parse(responseContent).RootElement.GetProperty("d");
            var locatorPath = locatorJson.GetProperty("Path").GetString();
            
            // 这里的Streaming Endpoint主机名可以提前配置，或者调用另一个REST接口获取
            var streamingHost = _configuration["Azure:StreamingEndpointHost"]; // 比如"youraccount.streaming.media.azure.net"
            var streamUrl = $"https://{streamingHost}{locatorPath}";

            return Ok(new { StreamingUrl = streamUrl });
        }
        catch (Exception ex)
        {
            return BadRequest($"调用REST API失败：{ex.Message}");
        }
    }

    // 获取Azure AD服务主体令牌
    private async Task<string> GetAadAccessToken()
    {
        var tenantId = _configuration["Azure:TenantId"];
        var clientId = _configuration["Azure:ClientId"];
        var clientSecret = _configuration["Azure:ClientSecret"];
        var resource = "https://rest.media.azure.net";

        var tokenRequest = new Dictionary<string, string>
        {
            ["grant_type"] = "client_credentials",
            ["client_id"] = clientId,
            ["client_secret"] = clientSecret,
            ["resource"] = resource
        };

        var tokenResponse = await _httpClient.PostAsync(
            $"https://login.microsoftonline.com/{tenantId}/oauth2/token",
            new FormUrlEncodedContent(tokenRequest));
        tokenResponse.EnsureSuccessStatusCode();

        var tokenContent = await tokenResponse.Content.ReadAsStringAsync();
        var tokenJson = JsonDocument.Parse(tokenContent).RootElement;
        return tokenJson.GetProperty("access_token").GetString();
    }
}

提示：这种方式需要在Azure AD注册服务主体，并给它分配AMS的访问权限，配置里要填好TenantId、ClientId、ClientSecret这些信息。

内容的提问来源于stack exchange，提问作者raspi surya